Abstract
Although commercial architecture is considered a relatively new term in the field of architecture, its origins can be traced back to ancient times and historical structures due to the importance of trade in the economies of various historical periods. The Ilkhanate period, marked by the decline of agricultural economy and the simultaneous flourishing of commercial economy, along with the construction of massive architectural complexes, serves as an excellent case for studying commercial architecture. The main question of this research is to what extent commercial objectives and goals were considered by the patrons, commissioners, and builders in the design and spatial organization of the Shanb Ghazan and Soltanieh complexes, and how the concept of commercial architecture can be applied to them. This research is qualitative in nature and adopts a descriptive-analytical approach. Data were collected through library research and field visits, and archaeological evidence and historical sources were compared in the analysis. The findings indicate that the Soltanieh and Shanb Ghazan complexes are the best examples for examining the presence of economic paradigms in the commercial architecture of the Ilkhanate period. In Shanb Ghazan, the presence of multiple gates, markets, roads, and international traders, and in the Soltanieh Dome, the construction of highways, industrial centers, factories, schools, and the central tomb of the Sultan, highlight the significant importance of commercial activities in the life of the Ilkhanid state. By constructing these two complexes, the Ilkhanid rulers sought to display their power and legitimacy among other Islamic civilizations and European states through the creation of monumental architectural complexes and commercial architecture. 
Keywords: Commercial Architecture, Ilkhanate Period, Shanb Ghazan, Soltanieh Dome.
Introduction
Our knowledge about the economy of cities and life within them during the 7th and 8th centuries AH (13th and 14th centuries CE) is very limited and ambiguous, often influenced by preconceptions shaped by the Mongols' actions during their invasions. It is likely that the Mongols' aversion to centralization, the recommendations of the Yasa (Chinggis law), and their emphasis on avoiding inactivity, which in turn highlighted the importance of trade, stemmed from their steppe geography. During the Ilkhanate period, due to reasons such as the destruction of agricultural infrastructure, droughts, and the decline of villages, the revenues from the agricultural economy were significantly lower compared to the commercial economy. Instead, the commercial economy reached its peak of prosperity, and, as will be discussed, international trade emerged for the first time during this period and thereafter. Until now, the architectural complexes of the Ilkhanid era have been examined from various perspectives, but no research has specifically addressed the commercial significance of these complexes. Existing studies have been limited to general observations and brief mentions in various articles. Among the most important of these structures are the Shanb Ghazan complex in Tabriz and the Soltanieh Dome complex. The main question of this research is to what extent commercial objectives and goals were considered by the patrons, commissioners, and builders in the design and spatial organization of the Shanb Ghazan and Soltanieh complexes, and how significantly the concepts of commercial economy influenced these structures. The authors hypothesize that commercial considerations played a crucial role in the construction of Ilkhanid architectural complexes, and that the Mongol rulers and their advisors deliberately and with premeditated planning created conditions to promote commercial prosperity within these complexes, the nearby cities, and the trade routes connected to them. The aim of this research is to study the manifestations of the commercial economy in the two architectural complexes of Shanb Ghazan and Soltanieh, relying on archaeological and historical data, in order to gain a better understanding of the concept of commercial architecture during the Ilkhanate period. This research is qualitative in nature and adopts a descriptive-analytical approach. Data were collected through library research and field visits, and in the analysis, archaeological evidence and historical sources were cross-referenced.
 
Discussion
During Ghazan Khan's era, the concept of Abwab al-Birr emerged, inspired by religious shrines in Iran, especially in Tabriz. Ghazan Khan began building the grand dome of Sham in 1296 CE, which became larger than the old city of Tabriz. The town featured symbolic elements such as a congregational mosque, schools, and the Sultan's tomb at the center, merging political power and religion. Merchants from Byzantium and Europe were required to trade in Shanb Ghazan's markets. The Ardabil-Ray Road influenced the city's internal roads and contributed to market expansion. Ghazaniyeh played a significant role in international trade, exchanging cultures, techniques, and artistic methods along trade routes.
Khwaja Rashid al-Din conceptualized Shanb Ghazan to exemplify the fusion of politics and religion. During the reigns of Ghazan Khan and Oljeitu, political, religious, and economic powers were integrated into the Soltanieh Citadel and Shanb Ghazan, reflecting the entirety of the power structure. Soltanieh encompassed all symbolic elements of governance. Schools promoting Shia Islam and the presence of Allamah al-Hilli legitimized the rulers' authority. Oljeitu’s alteration of trade routes concentrated the main pillars of governance in his new city, significantly impacting Tabriz’s status and facilitating the transportation of goods.
 
Conclusion
Among the most important cities, towns, and complexes established during the Ilkhanate period were Soltanieh and the Shanb Ghazan complex during the Muslim era of the Ilkhans. Although political, religious, and climatic factors played a role in the construction of both, as mentioned earlier, the political and religious reasons for establishing these cities and complexes were ultimately tied to economic considerations. It is also important to note that during the discussed centuries, separating political and economic affairs was not a straightforward task. During their Muslim era, the Ilkhans enjoyed political and religious legitimacy in Iran, and their primary goals were to reform and revitalize the economy while showcasing their power and legitimacy on both regional and international levels. The complexes of Soltanieh and Shanb Ghazan are the best examples for examining the presence of economic paradigms in Ilkhanid architecture. In Shanb Ghazan, the presence of multiple gates, markets, roads, and international merchants who were required to unload their goods there first highlights the city's commercial significance. It is likely that along the trade routes from Ghazaniyeh to the west, various cultures, techniques, and artistic methods were also exchanged. By constructing major trade highways, commercial and industrial centers, religious schools, factories, densely populated neighborhoods, and his own mausoleum in Soltanieh, Oljeitu concentrated all the elements and manifestations of the main pillars of governance—political, religious, and economic power—in one place, significantly impacting the status of Tabriz. It can be said that the Soltanieh complex had multiple functions, the most important of which was the political institution's exploitation to display power and legitimacy among other Muslim nations and European states through the construction of monumental architectural complexes and the assertion of commercial economic power in the strategically significant city of Soltanieh.